WO 97/42985 discloses a wound dressing comprising a layer of absorbent foam material which includes a pattern of holes. The holes open out on that side of the foam material which lies proximal to the wearer's skin when the dressing is worn, and the layer of foam material is coated with a layer of skin-adhering hydrophobic gel, wherein those end parts of the walls of the holes in the foam material that lie proximal to the wearer's skin when the dressing is worn are gel-coated. Nothing is disclosed about adding compounds affecting absorption to the dressing.
EP-A1-1 486 523 and U.S. Pat. No. 4,937,273 both relate to polyurethane foams containing antimicrobial silver bound to zeolite particles. Nothing is disclosed about adding compounds affecting absorption to the dressing.
GB-A-1 507 232 discloses a polyurethane foam which is intended to resemble a natural sponge. The foam contains the pigment Calcotone Green. Nothing is disclosed about neither wound dressings nor activated carbon particles.
EP-A-1 486 523 relates to a polyurethane foam containing polymeric inorganic particles. The foam could be used in a mattress or sanitary mat. Nothing is disclosed about neither activated carbon particles nor wound dressings.
US 2001/0003757 A1 and EP-A1-0 387 607 describe polyurethane foams containing electroconductive carbon black. The foams are intended to be used as an electroconductive elastic member. Nothing is mentioned about neither activated carbon particles nor wound dressings.
U.S. Pat. No. 5,065,752 shows a polyurethane foam containing superabsorbent particles. The foam could be used in wound dressings. Nothing is disclosed about activated carbon particles.
There is a need for materials that can be used in wound dressings and that possess improved absorption characteristics compared to the existing materials used in wound dressings available on the market. Important absorption characteristics are the maximum or accumulated absorption capacity, i.e. the ability to absorb large volumes of wound exudate in case of heavily exuding wounds, and the retention capacity, i.e. the ability of the material to resist static pressure, such as may occur in relation to pressure ulcers and in treating e.g. venous leg ulcers when often a combination of absorbing dressings and compression bandages is applied.